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watchdog: Convert ep93xx driver to watchdog core
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Convert the ep93xx_wdt driver to the watchdog framework API.

Also, use the dev_<fmt> functions instead of pr_<fmt> for logging.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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H Hartley Sweeten authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent fb35a5a commit e12a679
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Showing 2 changed files with 55 additions and 149 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -219,6 +219,7 @@ config MPCORE_WATCHDOG
config EP93XX_WATCHDOG
tristate "EP93xx Watchdog"
depends on ARCH_EP93XX
select WATCHDOG_CORE
help
Say Y here if to include support for the watchdog timer
embedded in the Cirrus Logic EP93xx family of devices.
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203 changes: 54 additions & 149 deletions drivers/watchdog/ep93xx_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,9 @@
* Authors: Ray Lehtiniemi <rayl@mail.com>,
* Alessandro Zummo <a.zummo@towertech.it>
*
* Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
* Convert to a platform device and use the watchdog framework API
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
Expand All @@ -23,189 +26,92 @@
* - Add a few missing ioctls
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#define WDT_VERSION "0.3"
#define WDT_VERSION "0.4"

/* default timeout (secs) */
#define WDT_TIMEOUT 30

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");

static int timeout = WDT_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=3600, default="
__MODULE_STRING(WDT_TIMEOUT) ")");

static void __iomem *mmio_base;
static struct timer_list timer;
static unsigned long next_heartbeat;
static unsigned long wdt_status;
static unsigned long boot_status;

#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1

#define EP93XX_WATCHDOG 0x00
#define EP93XX_WDSTATUS 0x04

/* reset the wdt every ~200ms */
#define WDT_INTERVAL (HZ/5)

static void wdt_enable(void)
{
writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
}

static void wdt_disable(void)
static void ep93xx_wdt_timer_ping(unsigned long data)
{
writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
}
if (time_before(jiffies, next_heartbeat))
writel(0x5555, mmio_base + EP93XX_WATCHDOG);

static inline void wdt_ping(void)
{
writel(0x5555, mmio_base + EP93XX_WATCHDOG);
/* Re-set the timer interval */
mod_timer(&timer, jiffies + WDT_INTERVAL);
}

static void wdt_startup(void)
static int ep93xx_wdt_start(struct watchdog_device *wdd)
{
next_heartbeat = jiffies + (timeout * HZ);

wdt_enable();
writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
mod_timer(&timer, jiffies + WDT_INTERVAL);

return 0;
}

static void wdt_shutdown(void)
static int ep93xx_wdt_stop(struct watchdog_device *wdd)
{
del_timer_sync(&timer);
wdt_disable();
writel(0xaa55, mmio_base + EP93XX_WATCHDOG);

return 0;
}

static void wdt_keepalive(void)
static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)
{
/* user land ping */
next_heartbeat = jiffies + (timeout * HZ);
}

static int ep93xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;

clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

wdt_startup();

return nonseekable_open(inode, file);
}

static ssize_t
ep93xx_wdt_write(struct file *file, const char __user *data, size_t len,
loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;

clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

for (i = 0; i != len; i++) {
char c;

if (get_user(c, data + i))
return -EFAULT;

if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
else
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
}
wdt_keepalive();
}

return len;
return 0;
}

static const struct watchdog_info ident = {
.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE,
.identity = "EP93xx Watchdog",
static const struct watchdog_info ep93xx_wdt_ident = {
.options = WDIOF_CARDRESET |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "EP93xx Watchdog",
};

static long ep93xx_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
int ret = -ENOTTY;

switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;

case WDIOC_GETSTATUS:
ret = put_user(0, (int __user *)arg);
break;

case WDIOC_GETBOOTSTATUS:
ret = put_user(boot_status, (int __user *)arg);
break;

case WDIOC_KEEPALIVE:
wdt_keepalive();
ret = 0;
break;

case WDIOC_GETTIMEOUT:
/* actually, it is 0.250 seconds.... */
ret = put_user(1, (int __user *)arg);
break;
}
return ret;
}

static int ep93xx_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
wdt_shutdown();
else
pr_crit("Device closed unexpectedly - timer will not stop\n");

clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

return 0;
}

static const struct file_operations ep93xx_wdt_fops = {
static struct watchdog_ops ep93xx_wdt_ops = {
.owner = THIS_MODULE,
.write = ep93xx_wdt_write,
.unlocked_ioctl = ep93xx_wdt_ioctl,
.open = ep93xx_wdt_open,
.release = ep93xx_wdt_release,
.llseek = no_llseek,
.start = ep93xx_wdt_start,
.stop = ep93xx_wdt_stop,
.ping = ep93xx_wdt_keepalive,
};

static struct miscdevice ep93xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ep93xx_wdt_fops,
static struct watchdog_device ep93xx_wdt_wdd = {
.info = &ep93xx_wdt_ident,
.ops = &ep93xx_wdt_ops,
};

static void ep93xx_timer_ping(unsigned long data)
{
if (time_before(jiffies, next_heartbeat))
wdt_ping();

/* Re-set the timer interval */
mod_timer(&timer, jiffies + WDT_INTERVAL);
}

static int __devinit ep93xx_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
Expand All @@ -226,26 +132,32 @@ static int __devinit ep93xx_wdt_probe(struct platform_device *pdev)

if (timeout < 1 || timeout > 3600) {
timeout = WDT_TIMEOUT;
pr_info("timeout value must be 1<=x<=3600, using %d\n",
dev_warn(&pdev->dev,
"timeout value must be 1<=x<=3600, using %d\n",
timeout);
}

val = readl(mmio_base + EP93XX_WATCHDOG);
boot_status = val & 0x01 ? 1 : 0;
ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;

watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);

setup_timer(&timer, ep93xx_timer_ping, 1);
setup_timer(&timer, ep93xx_wdt_timer_ping, 1);

err = misc_register(&ep93xx_wdt_miscdev);
err = watchdog_register_device(&ep93xx_wdt_wdd);
if (err)
return err;

pr_info("EP93XX watchdog, driver version " WDT_VERSION "%s\n",
dev_info(&pdev->dev,
"EP93XX watchdog, driver version " WDT_VERSION "%s\n",
(val & 0x08) ? " (nCS1 disable detected)" : "");
return err;

return 0;
}

static int __devexit ep93xx_wdt_remove(struct platform_device *pdev)
{
wdt_shutdown();
misc_deregister(&ep93xx_wdt_miscdev);
watchdog_unregister_device(&ep93xx_wdt_wdd);
return 0;
}

Expand All @@ -260,16 +172,9 @@ static struct platform_driver ep93xx_wdt_driver = {

module_platform_driver(ep93xx_wdt_driver);

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=3600, default="
__MODULE_STRING(WDT_TIMEOUT) ")");

MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>,"
"Alessandro Zummo <a.zummo@towertech.it>");
"Alessandro Zummo <a.zummo@towertech.it>,"
"H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_DESCRIPTION("EP93xx Watchdog");
MODULE_LICENSE("GPL");
MODULE_VERSION(WDT_VERSION);
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